Apparatus for bending continuous cast slabs

ABSTRACT

A starting bar with a unique head portion is connected to a continuous cast slab, and the bar-head portion coacts with a unique roller apron to effect bending of the continuous cast slab from the vertical toward the horizontal position.

United States Patent Kurt Reinfeld; Emmanuel V. Gouye, both of Pittsburgh, Pa.

Apr. 4, 1969 Sept. 7, 1971 Koppers Company, inc.

Inventors Appl. No. Filed Patented Assignee APPARATUS FOR BENDING CONTINUOUS CAST SLABS I 8 Claims, 9 Drawing Figs.

11.8. C1 164/274, 164/282 Int. Cl B22d 1 H08 164/82, 89,

[56] References Cited UNITED STATES PATENTS 3,157,920 11/1964 Hess 164/282 X 3,305,899 2/1967 Saunders 164/274 3,324,934 6/1967 Hess et al 164/274 3,314,115 4/1967 Saunders et 164/282 3,370,641 2/ 1968 Greenbarger 164/282 3,429,366 2/1969 Cruger et a1. 164/274 Primary Examiner-R. Spencer Annear Attameys-Sherman H. Barber and Olin E. Williams ABSTRACT: A starting bar with a unique head portion is connected to a continuous cast slab, and the bar-head portion coacts with a unique roller apron to effect bending of the continuous cast slab from the vertical toward the horizontal position.

PATENTEU SEP new 3,60 375 sum 2 or 2 INVENTORS KURT REM/FIELD 6- EMMANUEL l 601/)5 JAN ZQM APPARATUS FOR BENDING CONTINUOUS CAST SLABS BACKGROUND OF THE INVENTION In the art of continuous metal casting, it has been relatively SUMMARY OF THE INVENTION Apparatus for bending continuous cast slabs comprises a starting bar having an articulated head portion joined releasably to the cast slab, the head portion coacting with rollers of an apron structure to produce bending forces in the slab whereby the slab is curved.

For a further understanding of the present invention and for advantages and features thereof, reference may be made to the following description taken in conjunction with accompanying drawings which show for the purpose of exemplification an embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention is illustrated in the drawing wherein:

FIG. 1 is a schematic side elevational view of apparatus in accordance with the invention, shown in a first position relative to a continuous casting mold;

FIG. 1a is a detailed perspective view of a portion of the apparatus of FIG. 1;

FIG. 2 is a schematic side elevational view of the apparatus of FIG. 1, shown in a second position;

FIG. 3 is a schematic side elevation view of the apparatus of FIG. 1, shown in a third position;

FIG. 4 is a schematic perspective view of the head portion of a starting bar in accordance with the invention;

FIG. 5 is a view along line V-V of FIG. 4; and

FIGS. 6-8 are schematic perspective views of modifications of the structure of FIG. 4.

DETAILED DESCRIPTION In FIG. 1, a conventional vertically reciprocable mold 11 of a continuous casting machine 13 is adapted for the casting of a continuous metal slab 15. The slab 15, like a continuously cast billet, or strand, has a liquid core that is retained by a relatively thin solid metal skin, which forms in the mold.

In FIG. 1, the bottom of the vertically reciprocable mold 11 is closed initially by the head end portion 17 of a starting bar 19 that comprises a generally rectangular shaped upper member 21, that is formed integrally with a rectangularly shaped lower member 23 (FIG. 4).

The upper member 21, as shown in FIGS. 4 and 5, has a pm rality of T-slots 25, each of which receives and holds temporarily a T-headed anchor bolt 27. All of the T-slots 25 are located on one side of the upper member 21, as shown in FIGS. 4 and 5; the side being the left-hand side as shown in the drawings or that side which is further from the center of curvature of the arcuate apron structure.

The lower member 23 has a straight flat surface 29 and an opposed arcuate surface 31 both of which converge toward the lower edge of the surface 29; both surfaces 29, 31 merging in a rounded lower end 33, as suggested in FIG. 1. From FIG. 4, it will be noted that the lower member 23 is somewhat narrower in width than the upper member 21.

The head end portion 17 may be constructed as a weldment having a hollow interior, or as a casting that is lightened in a known manner. In any event, one entire head portion is interchangeable with the other head portions whereby they are reuseable many times. Only the T-headed anchor bolts 27 are expendable and are not recoverable or reuseable.

Attached to the sides of the upper member 21, by means of pivot pins 35, is one end of the articulated chain-type starting bar 19, which is comprised of a plurality of elongate links 37. The individual links 37, at the head end of the starting bar 19, are pivotably interconnected by pins 39.

Just below the lower edge 33 of the lower member 23, the links 37 on one side of the starting bar 19 are cross connected to corresponding links on the other side of the starting bar .19 by through pivot pins 41. Around each pivot pin 41 there is a spacer tube 43 that maintains the links 37 on opposite sides of the starting bar 19 in a proper spaced-apart relation.

Associated with the starting bar 1'9 hereinbefore described is a supporting apron structure 45 which comprises a plurality of pairs of opposed horizontally disposed rollers 47, 49.

In FIG. 1, the opposed pairs of horizontally disposed rollers 47 are smaller in diameter than the rollers 49, and the smaller rollers 47 are disposed vertically from just below the bottom of the mold 11 to a level some preselected distance, say 6 or 7 feet, below the mold. Below such a preselected level, the larger rollers 49 are arranged on the arc of a circle having a radius that is suited to the size of the strand being cast.

The aforementioned level marks :a transition from straight to curved, and at such a level the two rollers 51, 53, vertically adjacent on the right-hand side of the apron structure 45, as viewed in FIG. 1, act as fulcrum rollers in a manner described hereinafter.

On the left-hand side of the apron structure 45, and above the rollers 51, 53, there are a plurality of horizontally arranged rollers 55. The rollers 55 may be arranged as shown in FIG. 1a, or in any other suitable manner. The rollers 55 of FIG. la are journaled in spaced apart vertical plates 57 that project outwardly and vertically from a heavy support structure59, that is fixed to some suitable immovable adjacent structure.

Also, on the left-hand side of the apron structure 45, there are two other rollers 61, 63, which are disposed on the arc of the apron 45.

FIGS. 6-8 illustrate three modifications of the head end portion 17 of the starting bar 19. In FIG. 6, the head end portion 65 is centrally slotted and receives one end link 67 of a pulling chain 69; the end link 67 being pivotally attached to the head end portion 65 by a pivot pin 71. T-headed slots 25, such as those of FIG. 5 will be provided in the head end portion 65.

In FIG. 7, a modified head end portion 73 is slotted also, but only enough to receive a tongue portion 75 of a flat link slab pulling chain 77; the tongue portion 75 being pivotally connected to the head end portion by a pivot pin 79. T-headed slots 25 will also be provided in member 73 as shown in FIG. 5.

In FIG. 8, a modified head end portion 81 is slotted plurally and receives in each slot a tongue portion 83 of a pulling chain 85; the pulling chain tongue portion 83 being a pivotally connected to the head end portion 81 by means of a pivot pin 87. Again, T-headed slots 25 will be provided in member 81 as shown in FIG. 5.

The apparatus of the invention operates in the following manner. The head end portion 17 of the starting bar 19, equipped with T-headed anchor bolts 27, is inserted into the bottom of the continuous casting mold 11 in the usual manner. After molten metal has solidified :around the bolts 27 sufficiently to form the cast slab, the pulling chain starting bar 19 moves downwardly under the influence of conventional pinch rolls (not shown).

The head end portion 17 of the starting bar 19 moves vertically downward until the lower end portion 33 contacts rollers 61, 63. Contact with rollers 61, 63 produces reactionary forces 89, 91 (FIG. 2) on the head end portion 17 that act substantially normal to the curve of the arcuate apron. Such reactionary forces 89, 91 urge the lower member 23 toward the normal to the vertical axis of the slab and toward the left, as

viewed in FIG. 2. Balancing reactionary forces 97 are produced by the bank of rollers 55, and they act toward the right, as suggested in FIG. 2.

Thus, the reactionary forces 89, 91, acting about the rollers 51, 53 as a fulcrum, induce bending forces in the slab 15. The head end portion 17, being pivotally connected to the pulling chain starting bar 19, is free to move relative to the pulling chain links 37, and as the slab 15 moves downward further, it is bent still further by the reactionary forces 89, 91.

Those skilled in the art will recognize many significant and important features of the invention among which is:

A feature of the invention is a starting bar head and a pulling link chain connected to the head and an apron structure and so constructed and arranged, that bending forces are applied to a continuous cast steel slab wherefore it is bent to the contour of the arcuate apron structure.

A feature of the invention is a starting bar with a head that is sufficiently long so that bending forces are exerted on the slab by the head acting as a lever.

A feature of the invention is a starting bar head which is articulated so as to transmit bending forces to the cast slab and therefore to bend the cast slab.

What We claim is:

1. Apparatus for withdrawing and bending a continuously cast metal slab formed in a mold containing molten metal comprising:

a. an articulated starting bar having,

i. a head end portion for temporarily closing the bottom of said mold and having opposed flat and arcuate surfaces,

ii. means releasably connecting said head end portion to said slab formed in said mold when said molten metal partially solidifies;

b. a slab supporting structure disposed beneath said mold and having,

i. a vertical portion axially aligned with said mold, and

ii. a coplanar arcuate portion having an axis tangent to the axis of said vertical portion and a center of curvature; and

0. means to withdraw said head end portion and said slab from said mold, said arcuate surface of said head end portion being shaped for engaging said arcuate slab supporting portion and exerting forces on said head portion that urge said slab to bend, it into alignment with the arcuate slab supporting structure portion.

2. The invention of claim 1 wherein:

a. said means to withdraw said head end portion and said slab is articulated and pivotally connected to said head end portion.

3. The invention of claim 1 wherein:

a. said head end portion comprises,

i. an upper member having a cross section that is substantially the same size and shape as the cross section of the mold at the bottom thereof, and

ii. a lower member having an arcuate surface disposed away from the center of curvature of the arcuate portion of the slab supporting structure.

4. in a continuous casting apparatus including a mold wherein molten metal partially solidifies and forms a cast slab, an articulate slab support, and an articulated link-type starting bar for sealing the bottom of said mold and for withdrawing said cast slab, the improvement comprising:

a. a head end portion of said starting bar having a cross section that is substantially the same size and shape as said mold and having one lengthwise surface that is planar and an opposite surface which tapers arcuately to merge with said planar surface in a lower arcuate edge for causing said slab to bend in said arcuate slab support; and

b. a link member pivotally connected to said head portion.

5. The invention of claim 4 wherein:

a. said head lportion has at least one elongate slot therein; b. said lm member has a tongue on one end that cooperates with said slot; and

c. a pin pivotally secures said tongue to said head portion.

6. The invention of claim 4 wherein:

a. said head portion has a plurality of elongate slots therein;

b. said link member has a plurality of tongues on one end each of which cooperates with a slot; and

c. a pin pivotally secures said tongues to said head portion.

7. The invention of claim 1 wherein:

a. said vertical portion includes a plurality of first rollers that are disposed in contact with said slab and that exert reactionary forces thereagainst, which forces are directed toward said center of curvature; and wherein b. said arcuate portion includes,

i. a second roller disposed below said plurality of first rollers and on the opposite side of said slab, said second roller coacting with the flat surface of said head end portion to produce fulcrum reactionary forces; and

ii. a third roller disposed below said second roller and on the same side of said slab as said plurality of first rollers, said third roller coacting with said arcuate surface of said head end portion and exerting reactionary bending forces on said head end toward said center curvature, whereby said head end portion induces bending forces in said slab that bend it to conform to said support structure.

8. In a continuous casting machine including a vertically disposed casting mold wherein molten metal partially solidifies to form a continuous cast strand, the improvement comprising:

a. a starting bar for closing temporarily the bottom said mold, said starting bar having;

i. a head end portion having a cross section that is sub stantially the same size and shape as said mold and having one surface that is planar and an opposite arcuate surface, both said surfaces being merged in a lower arcuate edge; and

ii. a link member pivotally connected to said head portion;

b. a strand supporting apron structure disposed below said mold and comprising:

i. a plurality of vertically spaced apart rollers arranged on opposed sides of said strand and that engage and exert reactionary forces on said starting bar head end portion for bending arcuately from the vertical toward the horizontal attitude. 

1. Apparatus for withdrawing and bending a continuously cast metal slab formed in a mold containing molten metal comprising: a. an articulated starting bar having, i. a head end portion for temporarily closing the bottom of said mold and having opposed flat and arcuate surfaces, ii. means releasably connecting said head end portion to said slab formed in said mold when said molten metal partially solidifies; b. a slab supporting structure disposed beneath said mold and having, i. a vertical portion axially aligned with said mold, and ii. a coplanar arcuate portion having an axis tangent to the axis of said vertical portion and a center of curvature; and c. means to withdraw said head end portion and said slab from said mold, said arcuate surface of said head end portion being shaped for engaging said arcuate slab supporting portion and exerting forces on said head portion that urge said slab to bend, it into alignment with the arcuate slab supporting structure portion.
 2. The invention of claim 1 wherein: a. said means to withdraw said head end portion and said slab is articulated and pivotally connected to said head end portion.
 3. The invention of claim 1 wherein: a. said head end portion comprises, i. an upper member having a cross section that is substantially the same size and shape as the cross section of the mold at the bottom thereof, and ii. a lower member having an arcuate surface disposed away from the center of curvature of the arcuate portion of the slab supporting structure.
 4. In a continuous casting apparatus including a mold wherein molten metal partially solidifies and forms a cast slab, an articulate slab support, and an articulated link-type starting bar for sealing the bottom of said mold and for withdrawing said cast slab, tHe improvement comprising: a. a head end portion of said starting bar having a cross section that is substantially the same size and shape as said mold and having one lengthwise surface that is planar and an opposite surface which tapers arcuately to merge with said planar surface in a lower arcuate edge for causing said slab to bend in said arcuate slab support; and b. a link member pivotally connected to said head portion.
 5. The invention of claim 4 wherein: a. said head portion has at least one elongate slot therein; b. said link member has a tongue on one end that cooperates with said slot; and c. a pin pivotally secures said tongue to said head portion.
 6. The invention of claim 4 wherein: a. said head portion has a plurality of elongate slots therein; b. said link member has a plurality of tongues on one end each of which cooperates with a slot; and c. a pin pivotally secures said tongues to said head portion.
 7. The invention of claim 1 wherein: a. said vertical portion includes a plurality of first rollers that are disposed in contact with said slab and that exert reactionary forces thereagainst, which forces are directed toward said center of curvature; and wherein b. said arcuate portion includes, i. a second roller disposed below said plurality of first rollers and on the opposite side of said slab, said second roller coacting with the flat surface of said head end portion to produce fulcrum reactionary forces; and ii. a third roller disposed below said second roller and on the same side of said slab as said plurality of first rollers, said third roller coacting with said arcuate surface of said head end portion and exerting reactionary bending forces on said head end toward said center curvature, whereby said head end portion induces bending forces in said slab that bend it to conform to said support structure.
 8. In a continuous casting machine including a vertically disposed casting mold wherein molten metal partially solidifies to form a continuous cast strand, the improvement comprising: a. a starting bar for closing temporarily the bottom said mold, said starting bar having; i. a head end portion having a cross section that is substantially the same size and shape as said mold and having one surface that is planar and an opposite arcuate surface, both said surfaces being merged in a lower arcuate edge; and ii. a link member pivotally connected to said head portion; b. a strand supporting apron structure disposed below said mold and comprising: i. a plurality of vertically spaced apart rollers arranged on opposed sides of said strand and that engage and exert reactionary forces on said starting bar head end portion for bending arcuately from the vertical toward the horizontal attitude. 